Question

表A Employee_ID（类型A）员工姓名员工编号（B型）员工姓名

表B Employee_ID（任何类型） Employee_MGR

我需要通过查询 Table C 如下（无需表格，无需创建视图）

Employee_ID（类型A）员工姓名员工_MGR 员工编号（B型）员工姓名 Employee_MGR

Answer 1

您只需要两次加入经理表，每种雇员ID类型一次。

如果我不指出这是一个糟糕的数据模型，我会很失落，但是我确定您已经知道了。

设置表格：

DECLARE @TableA TABLE
  (
    [Employee_ID(Type A)] INT
   ,[Employee_Name]       VARCHAR(20)
   ,[Employee_ID(Type B)] INT
   ,[Employee Name]       VARCHAR(20)
  );

INSERT
  @TableA
  (
    [Employee_ID(Type A)]
   ,Employee_Name
   ,[Employee_ID(Type B)]
   ,[Employee Name]
  )
VALUES
  (1,'Bob',2,'Robert')
 ,(3,'Sue',4,'Susan');

DECLARE @TableB TABLE
  (
    [Employee_ID(Any Type)] INT
   ,[Employee_MGR]          VARCHAR(20)
  );

INSERT
  @TableB
  (
    [Employee_ID(Any Type)]
   ,Employee_MGR
  )
VALUES
  (1,'Mary')
 ,(2,'Helen')
 ,(3,'Joe')
 ,(4,'Harry');

DECLARE @tableC TABLE
  (
    [Employee_ID(Type A)]  INT
   ,[Employee_Name]        VARCHAR(20)
   ,[Employee_MGR(Type A)] VARCHAR(20)
   ,[Employee_ID(Type B)]  INT
   ,[Employee Name]        VARCHAR(20)
   ,[Employee_MGR(Type B)] VARCHAR(20)
  );

这是您的最终查询：

INSERT
  @tableC
  (
    [Employee_ID(Type A)]
   ,Employee_Name
   ,[Employee_MGR(Type A)]
   ,[Employee_ID(Type B)]
   ,[Employee Name]
   ,[Employee_MGR(Type B)]
  )
SELECT
  emp.[Employee_ID(Type A)]
 ,emp.Employee_Name
 ,mgrA.Employee_MGR
 ,emp.[Employee_ID(Type B)]
 ,emp.[Employee Name]
 ,mgrB.Employee_MGR
FROM
  @TableA AS emp
  JOIN
    @TableB AS mgrA
      ON
      mgrA.[Employee_ID(Any Type)] = emp.[Employee_ID(Type A)]
  JOIN
    @TableB AS mgrB
      ON
      mgrB.[Employee_ID(Any Type)] = emp.[Employee_ID(Type B)];

这就是给你的东西：

SELECT
  *
FROM
  @tableC;

+---------------------+---------------+----------------------+---------------------+---------------+----------------------+
| Employee_ID(Type A) | Employee_Name | Employee_MGR(Type A) | Employee_ID(Type B) | Employee Name | Employee_MGR(Type B) |
+---------------------+---------------+----------------------+---------------------+---------------+----------------------+
|                   1 | Bob           | Mary                 |                   2 | Robert        | Helen                |
|                   3 | Sue           | Joe                  |                   4 | Susan         | Harry                |
+---------------------+---------------+----------------------+---------------------+---------------+----------------------+

在多列中使用SQL Vlookup，而另一张表具有单个列

1 个答案: